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rear wiper spontaneous on, not not working


New Member
Hello fellow Tec heads,
Our 2004 Viano has a rather strange issue. One day the rear wiper just started to wipe, and I had to remove the 30A fuse to top it.
After a few days I replace the fuse (cause it finally stopped raining) and it work again as normal. This morning, it started to move, then stop and it is dead. Fuse is OK.
Anyone else experience this and possibly have a solution?

I was thinking either: a relay is bad (which one $ ), defective rear wire unit ($$) or MCU (since it seems to control everything $$$). Any tips would be grateful. I like to fix things myself cause it's very rewarding and saved money I can spend on other things for the Van.
There are several U Tube vids mentioning that for Vito's the water gets into the wirer motor assembly and shorts it out. Before I tear the whole back apart to see I'm really hoping a simple relay could do the trick.

Many thanks to any and all suggestions.
Sincerely yours,
The Dutch Yankee


Active Member
I can't really advise on your specific issue but if it were me I'd follow the usual electrical diagnosis of starting the most likely and cheap (relay) and gradually ticking off potential problem areas until you get to the root cause. My suspicion is the motor electrics but just a suspicion. Good luck and keep us posted


New Member
Following up on the rear wiper system, it’s the motor self which failed, either from the washer fluid leaking or EOL (end of life, 17years old). I have power to the motor but there is a PCBA ( printed circuit board assembly) which is part of the motor which is most likely the issue.
I never found any relays but in doing due diligence on the WWW it is a known common issue. New part ranges from €102 MB original part to €82 Chinese knock off. plus new rubber seal for €2.
I think original parts is the way I’m going to go. Doing it myself saves me €102 and allows me to inspect how and why it can happen, perhaps finding the root cause. More to follow, once parts and warm weather arrives.